it is a great mill, I just ran it yesterday againstall kinds of upper end mills, I had no probs running them down on straight, the Novarossi .21bf will haul the mail, and its cheap, but the quality is no joke...its not even really a budget engine IMO, only its pricetag.

+2.....21BF is what I started out with (and am still running) in my RC8. Very reliable, EASY to tune and cheap. Plus you specified that you wanted a torque engine. The .21bf fits the bill nicely....

break in engine with a NR 6 plug............when you re ready to race tune, install an O'donnell 99 plug..........The best all around combo is a NR 9853 w/ short header...........the next option would be an Ofna 053 w/ short header(comes with it) its a pop can pipe, but makes good power with the bf. Lots of pipes will work, it ultimately boils down to your application. I am currently running a TTR/AE 2035, and Im not really feeling it yet, I am running a conical smooth flow header, thats what Im not liking I think, ordering a Nova 9853 setup soon.

out of the 2 that you have listed i would get the ninja jx, it will give you similar performance as the speed but at a cheaper price, it also has a little more bottom end power, they both are very easy to tune engines